Yellow azo dye.



UNITED STATES PATENT ornrcn.

ADOLF KUGHENBECKER, OF HOOHST-ON-THE-MAIN, GERMANY, ASSIGNOR TOFARBWERKE VORM. MEISTER LUOIUS & BBI I'NING, OF HOCHST- ON-THE-MAIN,GERMANY, A CORPORATION OF GERMANY.

YELLOW AZO DYE.

Specification of Letters Patent.

Patented Dec. 25, 1906.

To all whom it may concern:

Be it known that I, ADOLF KL'CHENBECKER, 1

Ph. D., chemist, a citizen of the Empire of Germany, residing atflochston-thc-Main, Germany, have invented certain new and usefulImprovements in Yellow Azo Dyestuffs, of whichthc following isaspecificatio'n.

I have found that yellowazo dyestufl's distinguished by their shade andfastness may i be obtained by combinin diazotizedmetaxylidin-ortho-sulfonic acic with yrazolonesul'fomc acids, theconstitution 0 which corresponds wlth the formula readily soluble inwater. The color of their solution is not changed by alkalies or acids.

In concentrated sulfuric acid they dissolvewith a yellow color and aredecomposed by reduction with tin and hydrochloric acid, with formationof meta-xylidin--ortho-sulfonic acid, besides a derivative ofpyrazolonesulfonic acid.

The dyestuffs dye wool in yellow sha les fast to light.

The manufa ture of these new dyestut'l's may be carrima out, F rinstance, as follows: 20.1 kilos of :.eta ."ylidin ortho sulfonic acidare dissolved with sodium carbonate and diazotized by adding 6.9 kilosof nitrite and thirty kilos of concentrated hydrochloric acid. The diazocompound is then introduced into a solution of 28.4 kilos ofl-parasulfophenyl 5 pyrazolone 3 carbonic acid (C dhSU ll:( l()()ll:()123:5) and thirty l ilos of calcined soda. After stirring, for severalhours the whole is heated to about centigrade, and the dyestull is thenisolated by adding hydrochloric acid and common salt. Filtered and driedit is a yellow pow- E der readily soluble in water and dyeing woolgreenish-yellow shades. 1 The solution of the dyestuff in conceni tratedsulfuric acid is yellow. On heatin j with tin and concentratedhydrochloric aci the dyestutl' yields meta-xylidin-ortho-sulfonic acidand a derivative of pyrazolone, i which derivative becomes violet whentreated with ferric chlorid. 1tdyes wool greenish yellow.

Having now described my invention, what I claim ist The new azo dyeswhich when filtered and dried are yellow powders yieldin when reducedwith tin and hydrochloric aci metaxylidin-ortho-sulfonic acids andderivatives of pyrazolone-sulfonic acids the constitution ofi theselatter corresponding to the formula:

with a yellow color not changed by alkalies or acids; soluble also inconcentrated sulfurie acid with a yellow color and dyeing woolgreenish-yellow shades fast to light.

In testimony that I claim the foregoing as my i nvcntion I have signedmy name in pres once of two subscribing witnesses ADOLF KUUHENBECKER.

Witnesses:

JEAN GRITND, CARL GRUND.

bonic acid, being readily soluble in water l

